Proper storage of wine has been a problem for hundreds of years. Containers used for storage range from amphorae in ancient times to wooden barrels and metal tanks in modern usage. When wine is exposed to air, compounds in the wine react with the oxygen in the air. These oxidized compounds substantially reduce and impair the quality of the wine. In the manufacture, and especially storage of wine, there is a continual need to prevent contact with air and hence reduce oxidation. This problem is particularly difficult to prevent in the conventional rigid barrels and tanks that are typically used for storage and aging. Due to sampling and evaporation, these containers are often partially full and the residual air in the headspace of the barrel or tank reacts with the remaining stored wine degrading it. Enormous effort is spent in wineries worldwide “topping” off these containers with fresh wine to keep them full to the brim. Wooden barrels have the additional problem that they are porous, and air can diffuse into the wine through the wood. In addition to the quality reduction due to oxidation, contact with air can also cause contaminating bacteria to grow, making the wine sour and undrinkable. This can lead to major loss and wastage.
Better methods for the storage of wine are essential because wine must often be stored for several years in order to develop characteristic flavors. It is essential during this aging process that the wine does not oxidize or spoil.